In certain types of content-based image retrieval/recognition systems, the central task of the management system is to retrieve images that meet some specified constraints.
Most image-retrieval methods are limited to the keyword-based approach via database queries. There are also methods that generate keyword-based via images (Example, LTU Technologies), which is fundamentally database queries based on computer-generated keywords. In this approach, keywords and the images together form a record in a table. The retrieval is based on the keywords in much the same way as the relational database. (Example: Microsoft Access).
The current invention does not use keywords, neither manually generated keywords or keywords generated via some algorithms. The current invention consists of a set of algorithms.
The user operation is generally divided into two phases: the learning phase and the search/recognition phase. In the learning phase, various types of processes, such as image preprocessing and image filtering are applied to the images. Then the images are sent to a recognition module to teach the module the characteristics of the image. The learning module can use various algorithms to learn the sample image(s). In the search/retrieval phase, the recognition module decides the classification of an image in a search directory or a search database.
A very small number of commercially available products exist which perform content-based image retrieval.
Informix Internet Foundation 2000 is an object-relational database management system (ORDBMS), which supports non-alphanumeric data types (objects). IIF2000 supports several DataBlade modules including the Excalibur Image DataBlade module to extend its retrieval capabilities. DataBlade modules are server extensions that are integrated into the core of the database engine. The Excalibur Image DataBlade is based on technology from Excalibur Technologies Corporation, and is co-developed and co-supported by Informix and Excalibur. The core of the DataBlade is the Excalibur Visual retrievalWare SDK. The Image DataBlade module provides image storage, retrieval, and feature management for digital image data. This includes image manipulation, I/O routines, and feature extraction to store and retrieve images by their visual contents. An Informix database can be queried by aspect ratio, brightness, global colour, local colour, shape, and texture attributes. An evaluation copy of IIF2000 and the Excalibur Image DataBlade module can be downloaded from Informix.
IMatch is a content-based image retrieval system developed for the Windows operating system. The software was developed by Mario M. Westphal and is available under a shareware license. IMatch can query an image database by the following matching features: colour similarity, colour and shape (Quick), colour and shape (Fuzzy), colour percentage, and colour distribution. A fully functional 30-day evaluation copy is available for users to assess the software's capabilities and can be downloaded from Mario M. Westphal's web site. The shareware version has a 2000 limit on the number of images that can be added to a database. A new version of the software was released on the 18 Feb. 2001.
The Oracle8i Enterprise Server is an object relational database management system that includes integral support for BLOBs. This provides the basis for adding complex objects, such as digital images, to Oracle databases. The Enterprise release of the Oracle database server includes the Visual Information retrieval (VIR) data cartridge developed by Virage Inc. OVIR is an extension to Oracle8i Enterprise Server that provides image storage, content-based retrieval, and format conversion capabilities through an object type. An Oracle database can be queried by global color, local color, shape, and texture attributes. An evaluation copy of the Oracle8i Enterprise Server can be downloaded from Oracle, Inc.